1. Field of the Invention
The present invention relates to a protein chip and more specifically, a protein chip in which proteins are densely arranged on a substrate without impairing their intrinsic functions, and the production method of the protein chip.
2. Description of the Related Art
Since array technology using DNA chips enables the simultaneous expression analysis of numerous genes, they have played an important role as a tool for studying genomics. In recent years, it has been proposed that similar array technology (protein chips) could even be employed with the proteins, which are the most complex and diverse molecules in living organisms, in order to elucidate their functions. Expectations are especially high with protein chips since they enable protein analysis using trace amounts of proteins and they can be applied not only to research but also to a wide range of fields such as clinical diagnosis, health monitoring, drug development, and environmental and food inspections. Information on a wide range of topics, ranging from the recognition mechanisms and dynamics of complex interactions among proteins to the quantitative analysis thereof is desired, and thus higher throughput processing using protein chips is an important issue.
When preparing protein chips, microcontact printing and ink-jet method have both conventionally been used as methods for densely arranging proteins. In microcontact printing, the minimum spot size of the protein printed is 2 μm. However, the ink-jet method disclosed in Japanese Laid-Open Patent Application No. 2005-69988 is able to print tiny amounts of protein droplets on about the order of picoliters in which a spot size of 50 to 500 μm is achieved. In both cases, spaces of a few micrometers to a few hundred of micrometers are required.
However, in order to carry out the analysis more effectively, proteins must be arranged in an even higher density. Thus, the development of a protein chip where proteins spotted at intervals on the order of one nanometer are expected. Moreover, in the conventional method of fixing proteins onto a substrate, the three-dimensional structures or activities of the proteins were not necessarily taken into account. Therefore, it was possible that the original functions of the proteins were impaired with the conventional technologies.